The present invention relates to automatic transmissions and, more particularly, to torque converter housing covers providing increased fluid flow within the torque converter.
In automatic transmissions, especially in the torque converters, it is desirable to maintain maximum fluid or oil movement through the torque converter. Maximum fluid flow in the torque converter increases lubrication and cooling of the turbine, stator and impeller blades within the torque converter. Thus, the increased fluid flow enhances the overall performance of the torque converter and the automatic transmission. Generally speaking, a torque converter includes a transmission input shaft, turbine, stator, impeller, piston, friction material, stator overrunning clutch and front cover. Ordinarily, oil flows through the input shaft onto the front cover. The oil flows radially and axially along the front cover passed the piston and friction material to lubricate and cool the turbine, stator and impeller.
It is believed that a centrifugal head exists between the turbine and piston assembly in the torque converter. It is further believed that this centrifugal pressure head is caused by the internal leakage at the area of the running clearance between the impeller outlet and turbine inlet. The centrifugal head is believed to cause the piston assembly to move forward toward the front cover housing of the torque converter. As the piston assembly moves forward, it acts to pinch off the oil flow at the friction material area thus reducing and starving the oil flow within the torque converter.
An existing front cover housing as explained above is illustrated in FIG. 1. Generally, the torque converter cover 1 includes a circular base 2 and a peripheral skirt 3 extending transverse to the base. Generally, the base 2 includes a cup 4 at its center. The interior surface 5 of the base 2 is generally continuous having several ribs at radial positions outward from the cup 4 to the skirt 3 to provide rigidity. The cover 1 is generally secured with the impeller housing to provide the front cover of the torque converter.
Accordingly, in order to maintain a maximum oil flow and the desirable effects thereof, it is desirable to counteract the centrifugal head which tends to restrict maximum flow. As costs are always an important consideration, it is desirable to provide means for achieving this goal which are relatively economical, as well as being highly reliable in operation. Also, the means would preferably be adapted to be combined with torque converters without substantial alteration of the torque converter.
Accordingly, the present invention provides such a device which acts to substantially increase fluid flow in the torque converter. The present invention provides means which act as a second impeller to counteract the centrifugal forces generated so as to thereby increase fluid flow within the torque converter housing. By increasing the fluid flow, the present invention also increases lubrication and cooling of the torque converter thereby aiding in improved life expectancy and reliability.
From the below detailed description taken in conjunction with the accompanying drawings and claims, other objects and advantages of the present invention will become apparent to those skilled in the art.